Steel scaffolding ladder



F. BRANDT. STEEL SCAFFOLDING LADDER. APPLICATION FILED JUNEZB. 1920.

Patented Nov. 28, 1922 Patented Nov. 2%, 1922.

I fur. a.

FOKKO BRANDT, OF KANSAS CITY, KANSAS, ASSIGNOB TO THE BRANDT 5c KRELLENGINEERING COMPANY, OF. KANSAS CITY, KANSAS, A. CORPORATION OF 7KANSAS.

STEEL SCAFEOLDING LADDER.

. Application filed June 28,

To'aZZ whom it may concern: I Be it known that I, FOKKO BRANDT, a citZen of the Republic of Germany, and resident of Kansas City,- in thecounty of W} andotte and State of Kansas, have invented a certain newand useful Improvement in Steel Scaffolding Ladders, of which thefollowing is a complete specification.

This invention relates to adjustable-ladder step clamps, and moreespecially to a ladder construction for towers, derricks and scaffolds,the object being to provide steps and clampswhich can be applied to orremoved from a standard or upright of such structures quicklyeconomically, and which, in conjunction with .the standard, constitutesan eflicient and safev ladder step or round. y

A furtherobject is to provide steps and clamps. which can be secured toor removed from the standard by one standing on a lower step, and thusprovide for an increase or reduction in the length of the ladder asneeded.

A still further object is toprovide a-lad- 'der step which can besecured safely in position at any desired points on a tubular standardof metal.

To these ends the invention consists in certain novel and usefulfeatures of construction and combinations of parts as hereinafterdescribed and claimed; and in order that it may be fully understoodreference is to be had to the accompanying drawing, in which Figure 1 isa fragmentary edge View of a ladder embodying the invention.

Figure 2 is a similar View with the clamp elements in inclined positionpreliminary to securing the step firmly against the standard orren'ioving it therefrom.

Figure 3 is a top view of the construction as shown by Figure 1.

Figure 1 shows a portion of a tower or derrick equipped with a ladderembodying the invention.

Referring to the drawing in detail, 1 indicates the standard shown inthis instance in the form of a tubular metal pipe, a plurality of thesestandards in conjunction with horizontal pipes 2, constituting ascaffold, derrick or tower, as disclosed by Figure 4:. In said figurethe standards 1 are preferably in the form of superposed see- 1920.Serial No. 392,383.

jecting lugs 6 which act as guards to prevent ones feet from slippingfrom the steps in a sidewise direction, and cast or otherwise rigidlyformed about the center of each step is a lug 7, which lug ifthe step isto be applied to a metal pipe standard, is formed with a concaved rearface 8, conforming to and adapted to fit against the standard, as

shown most clearly by Figure 3.

A U-shaped clamp v9 terminates at the ends of its arms in upwardly andrearwardly facing hooks 10, and the lower portion of the saddle parts ofthe clamps constitute a concave internal face 11 conformingapproximately to the standard, and merging into an upper inclined face12 which, when the clamp is in operative position, diverges upwardlywith respect to the standard, as indicated most clearly by dotted linesin Figure 1. The upper portion of the saddle parts of the clamp isformed with a rearward projection 13 and mounted therein is a clampingscrew 14 which is withdrawn to substantiate a position shown by Figure2,

when the clamp is to be applied in operative position or removed fromsuch position, as indicated in Figure 2.

In securing a step in position, the same is fitted against the standardwith the concave face 8 of the block in direct contact with thestandard. The clamp is then fitted astride the standard and tilted sothat its inclined face 12 shall engage the standard and its hooks shallunderlie and engage the step at opposite sides of the lug 7, as shown byFigure 2. The clamping screw is then turned to advance it and cause itto bear against the standard, this action tending to retilt the clampand slide the step upwardly on the standard until the block is oppositethe clamping screw, by which time the lower or vertical face 11 of theclamp is approximately parallel with and engaging the standard, and theends of the hook are overard.

Assuming that the clamping screw is properly adjusted, it will beobvious that it is impossible for the step to shift its position in anydirection, and hence it constitutes a safe and strong support for aperson ascending or descending the ladder, as any increase in load uponthe step tends to cause the lug to clamp more firmly against thestandard because the relation of the parts is such that the clamp andstep can not slide downward without first effecting tilting action ofthe former. It is also obvious that as the arms of the clamp fit snuglyagainst opposite sides of the standard no lateral shifting of the lattercan occur.

I claim:

1. In a ladder, a standard, a step fitted against the standard, a clampengaging the standard at the opposite side thereof from said step, and aclamping screw mounted in the clamp and engaging the standard andtending to tilt the clamp to cause the same to'press forwardly againstthe standard and rearwardly against the step to clamp the latter firmlyagainst the standard.

2. In a ladder, a standard, a step fitted against the standard, aU-shaped clamp engaging the rear face of and projecting forwardly at theside of the standard and terminating in upwardly and rearwardly facinghooks engaging the step, and means tending to tilt the clamp to causethe same to press against the standard in a forward direction and thestep to press against the standard in a rearward direction.

3. In a ladder, astandard, a step fitted nae-rose against the front sideof the standard, a if shaped clamp fitting astride the standard andterminating at the front ends of its arms in hooks underlying andengaging the front and upper sides of the step; said clamp comprising alower Vertical portion and an upper inclined portion, and a clampingscrew extending through the inclined portion and engaging the standardand tending to tilt the clamp to clamp the lower portion thereof againstthe standard and cause the hooks thereof to clamp the step against thestandard.

4:. In a ladder, a standard, a step fitted against the front side of thestandard, a U-shaped clamp fitting astride the standard and terminatingat the front end of its arms in hooks underlying and engaging the frontand upper sides of the step; said clamp comprising a lower verticalportion and. an upper inclined portion, and a clamping screw extendingthrough the inclined portion and engaging the standard and tending totilt the clamp to clamp the lower portion thereof against the standardand cause the hooks thereof to clamp the step against the standard; saidstep terminating at its ends in upwardly projecting lugs.

5. In a ladder, a standard, a member fitted against the standard andforming a step, clamp engaging the step member, and a clamping elementmounted in the clamp and engaging the standard and tending to causerelative tilting movement of the step member and clamp to clamp them inposition on said standard.

In testimony whereof I hereunto aflix my signature.

FOKKO BRANDT.

